Free Calculator
Insulation Depth to R-Value Calculator
Measure the insulation on your attic floor and instantly see your current R-value — and whether you've reached the R-38 Florida standard.
Measure the depth of the insulation on your attic floor with a ruler.
Your estimated current R-value
R-15
Based on blown fiberglass (~R-2.5/inch), that's below the R-38 Florida standard — you'd add about 9.2″ more to get there.
R-per-inch varies by product — your insulation’s bag or coverage chart is the exact spec. Settling, gaps, and compression also lower real-world R-value.
Estimates are for planning only and based on typical Central Florida homes and 2026 pricing for blown-in fiberglass. Your exact price depends on attic access, existing insulation condition, and whether removal is needed — confirmed free during your inspection.
The fastest way to know if your attic is under-insulated is to measure it. Grab a ruler, check the depth of the loose insulation on the attic floor, and enter it here — you'll get your current R-value and how far you are from R-38.
Most Florida homes that were never upgraded come in well under R-38, which is why cooling bills run high in summer.
What goes into this estimate
Measure at the attic floor. Check the depth in a few spots — insulation can settle unevenly.
Get your current R-value. Depth × ~2.5 per inch for blown-in fiberglass.
See the gap to R-38. We show the inches and R-value you'd add to reach the Florida standard.
Frequently asked questions
How do I check my attic insulation R-value?
Measure the depth of the insulation with a ruler and multiply by the R-per-inch of the material (about 2.5 for blown-in fiberglass). Enter your depth above for the answer.
How much insulation should be on my attic floor in Florida?
Enough to reach R-38 — about 13–16 inches of blown fiberglass, or less if it's cellulose or spray foam.
My insulation looks uneven — what depth do I use?
Measure a few spots and use an average. Settling and gaps are common and reduce effective R-value.
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